denoux



May 26, 1931. DENOUX 1,806,598

ACOUSTIC RECEIVER Filed Dec. 19, 1929 2 Sheets-Sheet 1 May 26, 1931. R.DENOUX ACOUSTIC RECEIVER Filed Dec. 19, 1929 2 Sheets-Sheet 2 PatentedMay 26, 1931 UNITED STATES RENE DENOUX, 0F PARIS, FRANCE ACOUSTICRECEIVER Application filed December 19, 1929, Serial No. 415,321, and inFrance July 6, 1929.

My invention relates to improvements in acoustic receivers of the typeused in connection with phonographs, loud-speakers, and analogousinstruments.

One of the objects of my invention is to provide an improved soundreflector in a device of the character indicated.

Another object is to provide an improved form of sound conveyor incombination with a reflector of the aperiodic type.

The particular feature of the sound conveying device is the fact that itis composed of two frusto-conical members disposed one within the otheron the same axis, with perforations provided in the inner member whichallow the sound waves of the inner member to pass into the outer member,the sound waves arriving at the inner member.

This disposition allows me to discriminate the waves in two sound bodieswhose constants agree with high and low sounds.

The particular feature of the reflector is the fact that it isconstituted by a polished glass surface preferably cut out from asphere, but which may be a plane surface if desired. With this device Iam able to produce total reflection effects which assure a large outputand the inertia due to the glass surface assures purity in the soundreflected. When the spherical reflector is used, either the convex orconcave side may be utilized according to the particular effectsdesired.

In the following description I shall not allude to the particular devicefor producing the sound as the same has no particular bearing on myinvention. My device is in the form of a unit which is readily adaptedto any of the well-known acoustic devices such as the tone arm extendingfrom the sound box in a phonograph, for example.

My invention will be more readily understood by those skilled in the artin the following detailed description when taken in connection with theaccompanying drawings forming part of this specification, and in which 5f j Fig. 1 is a vertical section taken along the line 11 of Fig. 2; and

Fig. 2 is a horizontal section taken along the line 2-2 of Fig.1.

Referring to the drawings more in detail, I have shown at 1 a flangedtube leading to the sound producing diaphragm which has not beenillustrated since it forms no particular part of my invention.

A flanged elbow 2 forms an extension of a frusto conical member 3. Thetube 1 carries a sleeve 1 mounted on balls 1'. The sleeve l carries acoupling sleeve 1 extending through a bracket 2 over which fits a flange2 of elbow 2. The flange bracket and sleeves are clamped together bymeans of a screw 2 and nut 2. Bracket 2 is secured to the housing of thedevice by means of two screws 2 Fitted into the interior of member 3, isa frusto conical member 4. Adjacent the smaller end of member 4 is an annular indentation 5 through which and adjacent to and extending throughthe member 4 are perforations 5'. The purpose of the indentation 5 is toprovide a larger space between members 3 and 1 adjacent the holes 5. Anopen housing 7 receives the ends of members 3 and e and directly infront of said members is disposed a glass sound reflector 6. A space 8is provided between the member 3 and housing 7 by means of spacing pins8. Additional spacing pins 8 are provided between members 3 and 4C.These spacing pins, in addition to supporting memhere 3 and 4, preventparasitic vibrations.

The glass reflector 6 is fitted into the end wall 10 of the housing 7and extending therethrough'is a pin 9 having a conical head 11,preferably. The said pin 9 also extends through the wall 10 and throughthe wall of the instrument in which my device is used, a part of whichis shown at 10. The whole is clamped together by means of a screw 12,screwed into pin 9 and beneath the head of which is inserted a washer13.

The operation of my device is as follows: The sound waves arrive fromthe sound producing device through the tube 1 and member 2 and set thesound transmitting medium consisting of the columns of air contained inmembers 3 and 4 into motion. 'Due to the diflerent size and shape of theair columns a discrimination is produced in the larly for speech andmusic.

It is to be understood that while I have d escribed my reflector inconnection with a double frusto-coni'cal sound conveying tube,

I may nevertheless employ the same witha 7 single tube.

If it is desired to obtain a very voluminous reproduction, I may reversethe position of the concavo-convex reflector so that it becomes aconvex-concave reflector in order to reflect all the sound waves to theexterior. In this case when the sound Waves strike the the small end ofsaid first tube, and also having a series of perforations adjacent thesmall end thereof, a plurality of spacing pins 7 for securing the largeend of said second tube within the large end of said first tube inspaced relation thereto, and a concavo convex sound reflector ofpolished glass disposed in said housing directly in front of said tubes.

In testimony whereof I hereunto aflix my signature;

RENE DENOUX.

reflector coming through one or both tubular members as above described,they strike against a convex surface and are reflected into the housingin fan shape. It is to be understood that I may change the radius ofcurvature to produce the result desired and even increase the samesubstantially to infinity so that a plane surface isproduced. Inthiscase underconsideration the sound may be less pure but it is morevoluminous. I

My improved sound reflector 6 is constructed of polishedglass and eithera'plane sur face or a spherical concavo-convex surface cut from a sphereor vice versa,,and consti- H tutes a new industrial product.

Having thus described my invent on what I I claim as new anddesire tosecure by Letters Patent is:

1. An acoustic device of the type described comprising an open housing,a tapered tube having its large end opening'into said housing, means atthe small end of said tube for connecting a sound producing devicethereto,

spacing pins for securing the large end ofsaid tube within saidhousing,a; second ta 7 pered tube having its small end fitted within thesmall end of'said ofirst'tuberand also having a series of perforationsadjacent the small end thereof, a plurality of spacing pins for securingthe large end of. said second tube within the large end of said firsttube in spaced relation thereto, and a sound reflector of polished glassdisposed in said housing directly in front of said tubes.

2. An acoustic device of the type described comprising anopen housing, atapered tube having its large end opening into said housmg, means at thesmall end ofsaid tube for connecting a sound producing device thereto,

spacing pins for securing the large end of said tube within saidhousing, a second taperedtubehaving its small end fitted within

